I have a Convoy M2 inbound, and I’m wondering if anyone can tell me the diameter of the driver and emitter. I only have 17 mm drivers on hand, and with my luck this thing will need a 20 mm.
(Waddya mean, leave it stock? Good Lord man!) 
Mine is at home but I'm 99% sure it's 17mm
16mm for the star. The driver is a 17mm soldered to a 20mm board that connects to the battery.
Thanks!